I have been watching the old "Perry Mason"TV show on ME TV. One thing that always comes up-when you see a character living in a cheap hotel room, the room invariably faces the street, and the windows admit the flashing light from the neon sign. This seems to be a common device in 1950s TV-who invented the genre?
I think it was real. In some places in my lifetime, it still was (I was born in 1980). I certainly remember little hotels in the Ozarks having flashing signs like that. Color TV! Cable! Vacancy!
You bet it’s real, and plenty still exist today, in run-down little towns, & bad neighborhoods in bigger ones.
The rooms closest to the signs are the cheapest.
Invariably, the blinds are busted, and won’t close right.
Those signs were cutting edge technology at the time. Neon was the plasma of the day. 
Just like the Seinfeld episode with the Kenney Rogers Chicken restaurant!
Magic Fingers!
BTW, how did the do the nigh scenes in these old B&W TV shows? Perry mason looks like they just put a filter over the lens, and filmed in daytime.
In a Mad Magazine catalog of movie props, one was a hotel with a different blinking sign outside each window. Maybe that’s the explanation…
Exactly. Google “shooting day for night.”
A good sample scene is the one from American Graffitti where they are walking along the dirt river road. I believe you can find short documentaries/features that show them shooting the scene in daylight and then the processed final “nighttime” scene.
It can be well done or utterly cheesy. Things like sunlight through branches and glittering off shiny surfaces often gives it away.
Hey, the moonlight is always **REALLY BRIGHT **on TV and in films. Just like daylight only with a gray or bluish tint.
And they are often filmed on another planet with multiple bright moons. You can see shadows falling in different directions.
What’s even better is the light-to-dark transition in older TV shows, mostly 1970s-80s. The character flips off a bedside light, for example, only to have the room immediately light up in blue. Sometimes it’s well-timed and believable, other times it’s like they flipped a blue-filter switch… or there’s a noticeable delay between the light going out and “blue darkness” coming up.
I don’t know if it’s changed, but up until quite recently at least, actors were not allowed to flip a real switch. By union rules, an electrician had to do it. So you often see a significant time discontinuity between, say, Archie Bunker flipping a switch and the light going on or off.
What different blinking signs? They always said either HOTEL or HOT L.
And the campfires in Westerns neither burn brightly nor cast shadows. And you can see everything around you perfectly, without having your night vision ruined.
I remember that one. The lettering is the same but the shapes are different: some horizontal, some vertical, some with arrows, some without, etc.
The same catalog contains various guns, such as the ones of Navarone (shipping not included).
Imagine being ninja’d with that one.
IIRC, the caption included “. . . an irritating neon flashing light outside the window.”
For cheesy see Plan. 9 from Outer Space
Which is exactly the way automatic exposure circuits work today with video cameras, including the change in color temperature until the compensation kicks in.
A blinking neon sign outside a cheap hotel room’s window is a key plot point in Hitchcock’s Vertigo.
John Ford would film his (B&W) landscape shots through a colored filter, not to pass off day as night, but because it brought out the contrasting shades in the clouds.
In the Gary Cooper Beau Geste it’s obvious that they shot day for night through a blue filter. The dark uniforms turn a lighter gray. And even though all the Frankenstein Halloween masks are green, that was selected by Jack Pierce because it filmed corpse gray.
Day for night should be easy to do convincingly. The main rule is Don’t Show the Sky, which photographs light even with a dfn filter in both color and b&w. Surprisingly few film makers seem to have figured this out. Some instances are so obviously day shots that the only way to tell it is supposed to be night is the cricket chirping that the sound guy laid in there.